<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        class People {
            constructor(name) {
                this.name = name
                this.age = 20
            }
            sayHi() {
                console.log(this)
            }
        }

        const zhangsan = new People('张三')
        zhangsan.sayHi() // 张三对象
    </script>
</body>
</html>